Hydroxyaryl-tetramenthyl-dehydropiperidines

ABSTRACT

1. A COMPOUND HAVING THE FORMULA   2-R1,3-R2,4-(2,2,6,6-TETRA(H3C-),4-Y-PIPERIDIN-Y-YL-),   5-R3,6-R4-PHENOL   WHEREIN R1 AND R4 ARE SELECTED FROM HYDROGEN, METHYL, ETHYL, N-PROPYL, ISOPROPYL, SEC-BUTYL, T-BUTYL, 1,1-DIMETHYLPROPYL, 1,1-DIMETHYLBUTYL, 2-OCTYL, CYCLOHEXYL, 1-METHYLCYCLOHEXYL, BENZYL, A,A-DIMETHYLBENYL AND PHENYL, R2 AND R3 ARE HYDROGEN, METHYL OR ETHYL GROUPS AND Y IS HYDROGEN, O OR METHYL.

United States Patent-JOHice 3,847,930 HYDROXYARYL-TETRAMENTHYL- DEHYDROPIPERIDINES Donald Richard Randell, Stockport, and Malcolm John Smith, Marple, England, assignors to Ciba-Geigy Corporation, Ardsley, N.Y. No Drawing. Filed Nov. 28, 1972, Ser. No. 310,181 Claims priority, application Great Britain, Nov. 30, 1971, 55,419/71; July 14, 1972, 32,947/72 Int. Cl. C07d 31/28 US. Cl. 260-297 R 6 Claims ABSTRACT OF THE DISCLOSURE New 4 (4' hydroxyaryl)-3,4-dehydro-2,2,6,6-tetramethylpiperidines are used as stabilisers for organic materials, especially for polymers.

The present invention relates to new piperidine derivatives and in particular to new 4-(4'-hydroxyaryl)-3,4-dehydro-2,2,6,6-tetramethyl piperidines, which are useful stabilisers for polymers.

According to the present invention, there are provided compounds having the general formula I:

H30 CH3 Y I and salts thereof, wherein the substituent X has one of the formulae H and III:

II III preferably the formula II, R R R and R in formula II being the same or different and each being hydrogen, a straightor branched chain alkyl residue having from 1 to 9, preferably 1 to 4 carbon atoms, a cycloalkyl residue having from 5 to 14, preferably 6 to 8 carbon atoms, an aralkyl residue having from 7 to 14, preferably 7 to 9 carbon atoms, or an aryl or alkaryl residue each having from 6 to 14, preferably 6 to 10 carbon atoms, Y is hydrogen, 0, a straightor branched alkyl residue having from 1 to 12 carbon atoms, an alkenyl or alkynyl residue having from 3 to 12 carbon atoms or an aralkyl residue having from 7 to 12 carbon atoms, Z is hydrogen, an alkyl or substituted alkyl residue having from 1 to carbon atoms, an alkenyl or alkynyl residue having from 2 to 20 carbon atoms, a cycloaliphatic residue having from 5 to 12 carbon atoms, an araliphatic residue having from 7 to 12 carbon atoms, an aromatic residue having from 6 to 12 carbon atoms or a'heterocyclic residue, or the group COZ wherein 2; has the same-significance as Z, or Z is a group 3,847,930 Patented Nov. 12, 1974 H CH3 CH CH CH3 H H CzHs H n-CaH1 H sec-C4110 H OH:

H t-ClHo H Sec-amyl P I 1 (1' th 1 1 1 11119 Y P DY H 1,1-dimethy1butyl Thus, although in particular instances, each of the substituents R R R and R may be other than hydrogen, for instance, they may each be methyl, it is preferred in general, that at least two of these substituents are hydrogen. In particular, it is preferred that R and/or R are non-bulky substituents for instance a hydrogen atom, methyl or ethyl groups. However, if when one of the substituents R and R is a bulky group such as a tbutyl group, then the other substituent is preferably hydrogen. Furthermore, it is to be understood that it is unlikely that bulky groups such as t-butyl groups will be situated on adjacent carbon atoms of the phenyl residue.

Apart from hydrogen and O, Y may also be a methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, n-hexyl, noctyl, n-dodecyl, allyl, a-methallyl, l0-undecenyl, benzyl, a-methylbenzyl, p-methylbenzyl or an a-naphthylmethyl residue. However, particularly preferred substituents Y are 0 and straightor branched alkyl groups having from 1 to 4 carbon atoms, the most preferred substituents Y being 0, hydrogen and methyl residues.

Examples of alkyl or substituted alkyl residues Z are methyl, ethyl, n-propyl, n-butyl, sec-butyl, t-butyl, nhexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-hexadecyl, n-octadecyl eicosyl, fi-hydroxyethyl and fi-cyanoethyl residues. Preferred alkyl and substituted alkyl groups Z are those having from 1 to 12 carbon atoms. t

When Z is an alkenyl residue having from 3 to 20 carbon atoms, examples of such residues are allyl, met- 3,4-Dehydro-4- 4'-n-butyloxyphenyl)-1-butyl-2,2,6,6-

tetramethylpiperidine Where 4 (4'-Acetyloxyphenyl -3 ,4-dehydro-2,2,6,6-tetramethylpiperidine 4 4-Acetyloxy-3 ',5'-dimethylphenyl) -3 ,4-dehydro- 2,2,6,6-tetramethylpiperidine 4 4-Acetyloxy-3 '-cyclohexylphenyl) -3 ,4-dehydro- 2,2,6,6-tetramethylpiperidine 4 3 ,5 '-Dimethyl-4'-octanoyloxyphenyl -3,4-dehydro- 2,2,6,6-tetramethylpip eridine 4 (4-B enzoyloxyphenyl -3,4-dehydro-2,2,6,6-tetramethylpip eridine 4 [4' (3 ",5 "-Di-t-butyl-4"-hydroxybenzoyloxy) phenyl] 3,4-dehydro2,2,6,6-tetramethylpiperidine 3,4-Dehydro-4 3-cyclohexyl-4'-hexanoyloxyphenyl) 2,2,6,6-tetramethylpiperidine 3,4-Dehydro-4( 3',5'-dimethyl-4'-dodecanoyloxyphenyl) 2,2,6,6-tetramethylpiperidine 3 ,4-Dehydro-4 3 -t-butyl-4'-ste aroyloxyphenyl) -2,2, 6,6-

tetramethylpiperidine 3,4-Dehydro-4 (4-n-butyryloxy-3 '-methylphenyl) 2,2,6,6-tetramethylpiperidine 4 (4-N-Methylcarb amoyloxyphenyl -3 ,4-dehydro- 2,2,6,6-tetramethylpiperidine 3,4Dehydro-4 4-N-butylcarbamoyloxy-3 '-methylphenyl -2,2,6,6tetramethylpip eridine 3 ,4-Dehydro-4 (4'-N-hexylcarb amoyloxy-3 -methy1- phenyl -2,2,6,G-tetramethylpiperidine 3,4-Dehydro-4 (3 ,5 '-dimethyl-4-N-dodecyl-carbamoyloxyphenyl -2,2,6,6-tetramethylpiperidine 3,4-Dehydro-4 3 '-t-butyl-4'-N-octa-decylcarbarnoyloxyphenyl) -2,2,6,6-tetramethylpiperidine Where 4- 4'-Acetyloxyphenyl) -3 ,4-dehydro-2,2,6,6-tetramethylpip eridinel-oxyl 4 3 -Cyclohexyl-4-hex anoyloxyphenyl -3 ,4-dehydro- 2,2, 6,6-tetramethylpiperidinel-oxyl 4 (4'-N-Methylc arb amoyloxyphenyl) -3 ,4-dehydro- 2,2,6,6-tetramethylpiperidine-l-oxyl N-substituted derivatives may also be prepared by a Leuckart, Wallach or Eschweiler-Clarke reaction by reacting the compound of formula IV with formic acid and the appropriate aldehyde or ketone. In this way, the N-methyl derivative may be obtained using formic acid and formaldehyde.

The compounds of formula I in which Y is other than 0 are isolated from the reaction mixture conveniently as their acid salts, and the free compounds may be liberated from the salts by treating the salts with the stoichiometric proportion of a base such as sodium hydroxide or sodium carbonate required to liberate the free compound of formula I. If desired, the compound of formula I may then be further purified by conventional techniques.

The present invention also provides a process in which a compound of formula I, wherein X has the formula II or III and Z is hydrogen, is produced comprising reacting the corresponding 2,2,6,6-tet:ramethylpiperidine-4-one or an inorganic or organic acid salt thereof with either a-naphthol or a phenolic compound having the formula:

6 wherein R R R and R have their previous significance.

Advantageously, the reaction is effected in the presence of an acidic catalyst such as sulphuric acid, p-toluene sulphonic acid or, preferably, hydrogen chloride, although other catalysts such as sulphur compounds, for instance mercaptans, may also be present, and in the presence of a solvent inert under the reaction conditions, for instance methanol, ethanol or 2-methoxy-ethanol.

The reaction is conveniently carried out at any temperature within the range of from 0 C. to the reflux temperature of the reaction mixture, or at higher temperature under pressure. The reactants may be employed in molar ratios of from 5:1 to 1:5 preferably from 3:1 to 1:3, especially in molar ratios of approximately 1:1.

Compounds of formula I in which Z is the group COZ where Z is as hereinbefore defined may be conveniently prepared by reacting a compound of formula I in which Z is hydrogen with an esterification agent such as an acid, an acid chloride, an acid ester or an acid anhydride or an agent capable of forming a urethane grouping with the compound of formula I, such as an alkyl, alkenyl, aralkyl or aryl isocyanate. The reaction is preferably conducted in a solvent inert under the reaction conditions such as benzene, toluene or xylene.

Compounds of formula I in which Y is as hereinbefore defined and Z is not hydrogen may be conveniently produced by reacting compounds of formula I in which Z is hydrogen with an alkali metal such as sodium or potassium followed by reaction with an alkylating, alkenylating, alkynylating or aralkylating agent such as an alkyl, alkenyl, alkynyl or aralkyl halide. The reaction is preferably conducted in a solvent inert under the reaction conditions such as benzene, toluene or xylene.

Examples of suitable compounds of formula V are phenol o-cresol, 2,6-xylenol, 2,3-xylenol, 2,5-xylenol, 3,5-xylenol, 2,3,6-trimethylphenol, 2,3,5,6-tetr'amethyl phenol, o-ethylphenol, m-ethylphenol, 2-ethyl-3-methylphenol, 2:6-diethyl phenol, o-n-propylphenol, 2:6-di-npropylphenol, o-isopropylphenol, m-isopropyl phenol, 2,6-di-isopropyl phenol, o-sec. butyl phenol, 2,6-di-sec. butyl phenol, o-t-butyl phenol, m-t-butyl phenol, 2-tbutyl-S-methyl phenol, 2-t-butyl-6-methyl phenol, 3-tbutyl-S-methyl phenol, 2,5-di-t-butyl phenol, 2,6-dit-butyl phenol, o-sec. amyl phenol, 2,6-di-sec. amyl phenol, o-(1,1-dimethylpropyl) phenol, 2,6-di-(1,1- dimethylpropyl) phenol, o-(1,1-dimethylbutyl) phenol, 2,6-di-(1,1-dimethylbutyl) phenol, o-2-octyl phenol, o-cyclohexyl phenol, o-(l-methyloyclohexyl) phenol, o-benzyl phenol, o-(u,d-dimethylbenzyl phenol) and o-phenyl phenol.

The present invention still further provides a composi tion comprising an organic material and a stabilising amount of a compound having the Formula I as hereinbefore defined.

Compounds of Formula I have been found to impart to polyolefines an exceptionally high degree of stability towards deterioration normally induced by the effects of ultra-violet radiation or exposure to heat. Moreover, this improved stability is achieved without affecting the colour properties of the treated polyolefine. The stabilisers of the invention provide effective light and/or heat stabilisation, especially for lowand high-density polyethylene and polypropylene and polystyrene as well as polymers of butene-l, pentene-l, 3-methylbutene-1, hexene-l, 4-methylpentene-1, 4-methylhexene-1 and 4,4-dimethyl-pentene-1, and also coand ter-polymers of olefines, particularly of ethylene or propylene.

Other organic materials susceptible to degradation by the effects of light and the properties of which are improved by the incorporation therein of a compound of Formula I include natural and synthetic polymeric materials, for instance natural and synthetic rubbers, the latter including, for example, homo-, coand ter-polyrners of acrylonitrile, butadiene and styrene.

Specific synthetic polymers include polyvinyl chloride, polyvinylidene chloride and vinyl chloride co-polymers, polyvinyl acetate as well as condensation polymers derived from ether, ester (derived from carboxylic sulphonic or carbonic acids), amide or urethane groupings. These polymers can, for instance, form the basis of surface coating media such as paints and lacquers having an oil or resin, for instance an alkyd or polyamide resin, base.

The amount of the compound of formula I which is incorporated into the organic material in order to achieve maximal protection against degradation by light varies according to the properties of the organic material treated and according to the severity of the light radiation and to the length of exposure. However, for most purposes it is sufiicient to use an amount of the compound of formula I within the range of from 0.01% to by weight, more preferably within the range of from 0.1% to 2% by weight based on the weight of untreated organic material.

The compounds of formula I may be incorporated into the polymeric material by any of the known techniques for compounding additives with a polymer. For example, the compound of formula I and the polymer may be compounded in an internal mixer. Alternatively, the compound of formula I may be added as a solution or slurry in a suitable solvent or dispersant, for instance an inert organic solvent such as methanol, ethanol or acetone to powdered polymer and the whole mixed intimately in a mixer, and the solvent subsequently removed. As a further alternative the compound of formula I may be added to the polymer during the preparation of the latter, for instance at the latex stage of polymer production, to provide pre-stabilised polymer material.

Optionally, the composition of the invention may contain one or more further additives, especially those used in polymer formulations, such as antioxidants of the phenol or amine type, U.V. absorbers and light protectants, phosphite stabilisers, peroxide decomposers, polyamide stabilisers, basic co-stabilisers, polyvinyl chloride stabilisers, nucleation agents, plasticizers, lubricants, emulsifiers, anti-static agents, fiame-protectants, pigments, carbon black, asbestos, glass fibers, kaolin and talc.

The present invention therefore includes binary, tertiary and multi-cornponent compositions containing the stabiliser of formula I together with one or more functional additives for polymers.

Examples of suitable antioxidants are those of the bindered phenol type such as those selected from the following groups:

(1) Phenolic compounds having the general formula Q( z)w 1 wherein Q is R is hydrogen or lower alkyl R is lower alkyl R" is alkyl group having from 6-24 carbon atoms w is an integer from 0 to 4.

Illustrative examples of the compounds shown above are di-n-octadecyl a-(3,S-di-t-buty1-4-hydroxybenzyl) malonate di-n-octadecyl a-(3 t butyl-4-hydroxy-5-methyl-benzyl) malonate which is disclosed in the Netherlands Pat.

No. 6,711,199, Feb. 19, 1968 8 di-n-octadecyl-a,u'bis-(3-t-butyl 4 hydroxy-S-methylbenzyl)malonate which is disclosed in the Netherlands Patent No. 6,803,498, Sept. 18, 1968.

(2) Phenolic compounds having the general formula Q-R. Illustrative examples of the compounds shown above are 2,6-di-t-butyl-p-cresol 2-methyl-4,6-di-t-butylpheno1 and the like. 2,6-di-Octadecyl-p-cresol (3) Phenolic compounds having the formula Illustrative examples of the compounds shown are: 2,2-methylene-bis (6-t-butyl-4-methylphenol) 2,2'-methylene-bis(6-t butyl-4-ethylphenol) 4,4'-butylidene-bis(2,6-di-t-butylphenol) 4,4'-(2-buty1idene)-bis(2-t-butyl-5-methylphenol) 2,2'-methylene-bis 6- (2-t-methylcyclohexyl) -4-methylphenol 2,2'-methylene-bis(3-t-butyl-5-ethylphenol) 4,4'-methylene-bis (3 ,5 -di-t-butylphenol 4,4'-methylene-bis(3-t-butyl-5-methylphenol) 2,2'-methylene-bis(3-t-butyl-S-methylphenol) and the like.

(4) Phenolic compounds having the formula Illustrative examples of such compounds are 2,S-di-t-butylhydroquinone 2,6-di-t-butylhydroquinone 2,5-di-t-butyl-4-hydroxyanisole (5) Phenolic compounds having the formula QSQ. Illustrative examples of such compounds are 4,4'-thiobis-(Z-t-butyl-S-methylphenol) 4,4-thiobis-(2-t-butyl-6-methylphenol) 2,2'-thiobis-(6-t-butyl-4-methylphenol) 4,4'-thiobis-(2-methyl-5-t-butylphenol) (6) Phenolic compounds having the formula Illustrative examples of such compounds are octadecyl-(3,S-dimethyl-4-hydroxybenzylthio)acetate dodecyl- (3,5 -di-t-butyl-4-hydroxybenzylthio -propionate (7) Phenolic compounds having the formula CH (CwH2w) Q. Q wherein T is hydrogen R or Q as defined above. Illustrative examples of such compounds are 1,1,3-tris(3,5-dimethyl-4-hydroxyphenyl)-propane 1, 1,3-tris 5-t-butyl-4-hydroxy-2-methylphenyl) -butane 1,1,5,5-tetrakis-(3'-t-buty1-4'-hydroxy-6-methylphenyl)- n-pentane (8) Phenolic compounds having the formula (5H; CH2 B 1 Q 2 CH3 B 7 l C 3 H213 wherein B B and B are hydrogen, methyl or Q, provided that when B and B are Q then B is hydrogen or methyl and when B is Q then B and B are hydrogen or methyl. Illustrative examples of such compounds are 1,4-di(3,S-di-t-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene Sorbitol hexa-[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate] 1,2,3-butanetriol tris- [3- 3,5 -di-t-butyl-4-hydroxyphenyl) propionate] Z-hydroxyethyl 7-(3-methyl-5-t-butyl-4-hydroxyphenyl) heptanoate Z-stearoyloxyethyl 7-(3-methyl-5-t-butyl-4-hydroxy phenyl)heptanoate 1,6-n-hexanediol-bis{ (3 ',5-di-t-butyl-4-hydroxyphenyl) propionate] The above phenolic ester stabilizers of sub-classes I,

II and 1H are more fully described in U.S. 3,330,859,

(12) Phenolic compounds having the formula where x is an integer of 1 or 2. Illustrative examples of such compounds are Di-n-octadecyl 3,5-di-t-butyl-4-hydroxybenzylphosph0nate Di-n-octadecyl 3-t-butyl-4-hydroxy-5-methylbenzylphosphonate Di-n-octadecyl 1-(3,S-di-t-butyl-4-hydroxyphenyl)- ethanephosphonate Di-n-tetradecyl 3,5-di-t-butyl-4-hydroxybenzylphosphonate Di-n-hexadecyl 3,5 -di-t-butyl-4-hydroxybenzylphosphonate Di-n-docosyl-3,5-di-t-butyl-4-hydroxybenzylphosph0nate Di-n-octadecyl 3,5-di-t-butyl-4-hydroxybenzylphosphonate The above di-(higher)alkyl phenolic phosphonates are more fully described in U.S. 3,281,505.

(13) Phenolic compounds having the formula wherein W and Q are defined above. Illustrative examples of such compounds are:

tris- 3,S-di-t-butyl-4-hydroxybenzyl iso cyanurate tris-(3-t-butyl-4-hydroxy-5-methylbenzyl)isocyanurate The above hydroxyphenylalkenyl isocyanurates are more fully described in U.S. 3,531,483.

The above phenolic hydrocarbon stabilizers are known and many are commercially available.

While any of the above mentioned antioxidants can be useful in combination with the ultraviolet light stabilizers of this invention, the preferred antioxidants consist of the hindered phenols in groups 1, 8, 9, 10, 11, 12 and 13 as mentioned above. The most preferred hindered phenols are those of groups 1, 9, 11, 12 and 13.

Further examples of antioxidants are those of the aminoaryl series for instance aniline and naphthylamine derivatives as well as their heterocyclic derivatives such as:

phenyl-l-naphthylamine phenyl-Z-naphthylamine N,N-diphenyl-p-phenyldiamine N,N'-di-sec.butyl-p-phenylenediamine 6Ethoxy-2,2,4-trimethyl-1,Z-dihydroquinoline 6-Dodecyl-2,2,4-trimethyl-1,2-dihydroquinoline Monoand di-octyliminodibenzyl and polymerised 2,2,4-triniethyl-1,2-dihydroquinoline.

Ultraviolet absorbers and light protectants include (a) 2-(2'-hydroxyphenyl)benzotriazoles, for instance methyl; 3,5-di-t-butyl; 5'-t-butyl; 5-chloro-3,5-di-t-bu tyl; 5-chloro-3'-t-butyl-5'-methyl; 3'-sec.butyl-5-tert.butyl; 3'-[a-methylbenzyl]-5'-methyl-; 3[a-methylbenzyl)-5'-methyl-5-chloro-; 4'-octoxy-; 3',5'-dit-arnyl; 3'- methyl-5'-carbomethoxyethyl; 5 chloro-3',5'-di-t-amyl derivatives.

12 (b) 2,4-bis-(2-hydroxypheny1)*6-alkyl-S-triazines, for instance the 6-ethyl or 6-undecyl derivatives. (c) Z-hydroxybenzophenones, for instance the 4-hydroxy, 4-methoxy, 4-octoxy-, 4-decyloxy-, 4-dodecyloxy-, 4,2, 4'-trihydroxy or 2-hydroxy-4,4'-dimethoxy derivatives. ((1) 1,3-Bis(2-hydroxybenzoyl)-benzenes for instance,

1,3-bis-(2'-hydroxy-4-hexyloxybenzoyl)benzene 1,3-bis-(2-hydroxy-4'-octoxybenzoyl)benzene 1, 3 -bis- (2'-hydroxy-4-dodecyloxybenzoyl benzene (e) Aryl esters from optionally substituted benzoic acids such as phenylsalicylate, octylphenylsalicylate, dibenzoyl resorcinol, bis-(4-tert.butylbenzoyl) resorcinol, benzoylresorcinol and 3,S-di-tert.butyl-4-hydroxy-benzoic acid-2,4-di-tert.butyl phenyl ester and -octadecyl ester and -2-methyl-4, 6-di-tert.butyl phenyl ester. (f) Acrylates, for instance a-Cyan0-fl,[3-diphenylacrylic acid ethylor iso-octyl ester a-carbomethoxy-cinnamic acid methylor butyl ester and N-(fi-carbomethoxy-vinyl)-2-methyl indoline.

(g) Nickel compounds such as nickel complexes of 2,2-

thiobis-(4-tert. octylphenol), for instance the 1:1 and 1:2 complexes, optionally having other ligands such as n-butylamine, triethanolamine or N-cyclohexyl-diethanolamine; nickel complexes of bis-(4-tert. octylphenyl) sulphone such as the 2:1 complex, optionally having other ligands such as Z-ethylcaproic acid; nickel dibutyl dithiocarbamates; nickel salts of 4-hydroxy-3,5- di-tert.butylbenzylphosphonic acid mono-alkyl esters such as the methyl-, ethylor butyl esters; the nickel complex of 2-hydroxy-4-rnethyl-phenyl-undecylketonoxime; and nickel-3,5-di-tert.buty1-4-hydroxy benzoate, and

(h) Oxalic acid diamides, for instance 4,4'-dioctyloxyoxanilide 2,2'-dioctyloxy-5,5-di-tert.butyl-oxanilide 2,2'-di-dodecycloxy-5,5'-di-tert.butyl oxanilide 2-ethoxy-5-tertiarybutyl-2'-ethyl-oxanilide 2-ethoxy-2'-ethyl-oxanilide mixtures of oand p-methoxy and ethoxy-disub stituted oxanilides and the compound of formula:

Phosphite stabilisers include triphenyl phosphite, diphenylalkyl phosphites, phenyl dialkyl phosphites, trinonylphenyl phosphite, trilauryl phosphite, trioctadecylphosphite, 3,9'-di-isodecyloxy-2,4,8,IO-tetraoxo 3,9 diphosphaspiro-(5,5)-undecane and tri-(4-hydroXy-3,5-ditert.butylphenyl phosphite.

Peroxide-decomposing compounds for polyolefin include esters of B-thiodipropionic acids, for instance the 1auryl-, stearyl-, myristylor tridecyl esters, salts of mercaptobenzimidazoles such as the zinc salt and diphenylthiourea.

Suitable polyamide stabilisers include copper salts in combination with iodides and/ or further phosphorus compounds and salts of bivalent manganese.

Basic co-stabilisers are, for example, polyvinylpyrrolidone, melamine, benzoguanamine, tn'allyl cyanurate, dicyandiamide, urea derivatives, hydrazine derivatives, amines, polyamides, polyurethanes, alkali and alkaline earth salts of higher saturated or unsaturated fatty acids such as calcium stearate.

Polyvinyl chloride stabilisers include orgauotin compounds, organo lead compounds and Ba/Cd salts of fatty acids.

Examples of nucleation agents are 4-tert.butyl benzoic acid, adipic acid and diphenylacetic acid.

As with the compound of formula I, any further additive is advantageously employed in a proportion within 13 the range of from 0.01% to by Weight, based on the weight of untreated polymeric material.

In binary combinations with one or more antioxidants listed above or in tertiary combinations with such antioxidants and U.V. absorbers listed above, the compounds of formula I provide very effective stabiliser packages in polyolefine formulations.

Some Examples will now be given. Parts and percentages are by weight unless otherwise stated.

Crystallisation of this material from a chloroformpetroleum (b.p. 6080 C.) mixture afforded 2.8 parts of the desired product melting at 175176 C. and having the following elemental analysis:

C H NO requires C, 79.68%; H, 10.36%; N, 4.65%. Found: C, 79.51%; H, 10.11%; N, 4.56%.

The Examples shown in the following Table II were prepared by a method similar to that described in Example 6.

TABLE II Analysis Reaction Required (percent) Found (percent) Example time, Molecular number R1 R2 R3 R4 hours M.P. formula C H N C H N 7 Us: H H CH: 24 181-3 C21H3JNO 79.95 10.54 4.44 79.91 10. 24 4. 03

/CH /CH CH: CH;

8 Z-octyl H H H 48 115-7 CHHUNO 80. 41 10. 86 4. 08 80. 62 10. 93 3. 9 5 9 PhCH: H H H 72 158-9 CQZHQINO 82. 8. 47 4. 36 82. 34 8. 23 8 EXAMPLE 1 EXAMPLE 10 Y Y YP Y 3,4-Dehydro-4- (4-hydroxy-2'-methylphenyl)-2,2,6,6-

ttitlamethylpipefidine tetramethylpiperidine hydrochloride 5.00 parts of triacetonamine hydrochloride and 4.90 parts of phenol were dissolved in 80 parts ethanol by warming. The solution was heated to reflux and dry hydrogen chloride gas bubbled through for 48 hours. After allowing the mixture to stand for 12 hours at 20 C., the solid precipitate was removed by filtration and washed with 20 parts of chilled ethanol. The solid was dissolved in 200 parts of water by warming and this solution made alkaline by the addition of 10% aqueous sodium carbonate solution.

After cooling to 20 C., the solid precipitate was removed by filtration and washed with 50 parts of cold water, and dried to afford 2.50 parts of the desired compound.

Crystallisation of the material from chloroformpetroleum mixture (b.p. 60-80 C.) yielded a sample melting at 193 to 195 C., and having the following elemental analysis:

C H NO requires C, 77.88%; H, 9.15%; N, 6.05%. Found: C, 77.76%; H, 9.29%; N, 5.76%.

The Examples shown in the following Table I were prepared by a method similar to that described in Example 1 using substantially molar quantities of reactants.

15.0 Parts of triacetonamine hydrochloride and 8.4 parts of meta-cresol were dissolved in 200 parts of ethanol and treated with hydrogen chloride gas Whilst the mixture was heated at reflux for 16 hours. The solution was cooled and evaporated to dryness under reduced pressure. The brown gum obtained was triturated with ethanol and ether to yield 10 parts of a white material which was mainly triacetonamine hydrochloride. After removal of this solid by filtration the filtrate Was evaporated to dryness under reduced pressure. The residue obtained was dissolved in water and extracted three times with ether. The ether extracts were discarded. The aqueous phase was made alkaline by the addition of 10% aqueous sodium carbonate solution and extracted three times with ether. The aqueous phase was discarded. The ethereal layer was dried and evaporated to dryness under reduced pressure. The residue was treated with a few parts of 10% aqueous hydrochloric acid, warmed and allowed to cool. The white crystalline hydrochloride which separated from solution was filtered off and washed with cold 10% hydrochloric acid. The material was dried and crystallised from ethanol-ether to afford 0.6 parts of the desired product having melting point 270 and the following elemental analysis:

TABLE I Analysis Re uired ereent Found ercent Example Reaction M.P., Molecular q (p (p number R1 R2 R3 R4 time,hours O. formula C H N C H N H H H 48 166-7 CrsHraNO 78.32 9.45 5.71 78.54 9.45 5.97 H H CH3 48 150-3 CnHzsNO 78.72 9.71 5.40 78.90 9.69 5.26 H H H 18 216-7 CrnHzoNO 79.39 10.17 4.87 79.41 10.23 4.74 H H H 72 203-4 21H3lNO 80.46 9.97 4.47 80.41 9.85 4.26

EXAMPLE 6 3,4-Dehydro-4- (3 '-tbutyl-4'hydroxy-5 '-methylphenyl 2,2,6,6-tetramethylpiperidine 15.0 Parts of triacetonamine hydrochloride and 12.8 parts of 6-t-butyl-ortho-cresol were dissolved in 250 parts of ethanol by warming. The solution was heated at reflux and dried hydrogen chloride gas was bubbled through for hours. After allowing the solution to cool to room temperature, the ethanol was evaporated off under reduced pressure. The residue was dissolved in water and extracted three times with ether.,The ethereal layer was discarded. The aqueous layer was made alkaline by treatmg it with a 10% aqueous solution of sodium carbonate. The solution was extracted three times with ether and the aqueous phase discarded. The ethereal phase was dried and evaporated to dryness to yield a brown/yellow solid.

0 4.97%; Cl, 12.58%. Found: C, 68.12%; H, 8.49%; N

C H NOHCl requires C, 68.18%; H, 8.58%; N,

4.97%; 01, 12.64%. EXAMPLE 11 3,4-Dehydro-4- 3 -phenyl4'-hydroxyphenyl) -2,2,6,6- tetramethylpiperidine 15.0 Parts of triacetonamine hydrochloride and 14.0 parts of o-phenylphenol were dissolved in 200 parts of ethanol by warming. The solution was heated at reflux and dried hydrogen chloride gas bubbled through for 96 hours. After allowing to cool to room temperature the ethanol was evaporated under reduced pressure. The residue was dissolved in water and extracted with ether three times. The ethereal layer was discarded. The aqueous layer was basified by treating it with a 10% aqueous solution of sodium carbonate. The solution was extracted with ether 15 three times and the aqueous phase discarded. The ethereal phase was dried and evaporated to dryness to yield a low melting point residue. The residue was dissolved in hot ethanol and treated with aqueous hydrochloric acid until the hydrochloride started to crystallise. After allowing the solution to cool to room temperature the salt was separated by filtration and recrysallised again from eth-.

and-10% aqueous hydrochloric acid. The purified hydrochloride was dissolved in waterethanol (9:1) and basified by treating with 10% aqueous sodium carbonate. The solid precipitate was removed by filtration, washed with water, dried and crystallised from petroleum ether (b.p. 100120 C.) to afford 2.2 parts of the desired product melting at 149 -151 C. and having the following elemental analysis:

C H NO requires C, 82.04%; H, 8.21%; N, 4.56%. Found: C, 81.97%; H, 8.26%; N, 4.31%.

EXAMPLE 12 3,4-Dehydro-4-(4'-hydroxynaphthyl -2,2,6,6tetramethylpiperidine 20.0 Parts of triacetonamine hydrochloride and 30.0 parts of 1-naphthol were dissolved in 250 parts of dry ethanol and treated with dry hydrogen chloride gas whilst the mixture was heated at reflux for 18 hours. The solution was cooled to room temperature and evaporated to dryness under reduced pressure. The brown residue was triturated with ethanol and ether to effect precipitation of a white solid which (9 parts) was separated by filtration. The solid was dissolved in a warm ethanol-water (1:1) mixture and the solution made alkaline with 10% aqueous sodium carbonate solution. The mixture was cooled and the precipitate separated by filtration and Washed with water. Crystallisation from a methanol-water mixture af forded the desired product melting at 101102 C. and having the following elemental analysis:

C H NO requires C, 81.10%; H, 8.24%; N, 4.98%. Found: C, 80.90%; H, 8.04%; N, 4.76%.

EXAMPLE 13 3,4-Dehydro-4-( 3,5-dimethyl-4'-hydroxyphenyl)- 1,2,2,6,6-pentamethylpiperidine 1.5 Parts by weight of 3,4-dehydro-4-(3',5'-dimetl1yl-4- hydroxyphenyl) 2,2,6,6 tetramethylpiperidine was dissolved in methanol and treated with 2 parts by weight of formic acid. The methanol was evaporated under reduced pressure and the resulting amine salt mixed with 2 parts by weight of 37% formaldehyde solution. Warming and further addition of formic acid effected solution. The solution was heated under a reflux condenser on a steam bath for four hours, poured into water and basified with sodium carbonate. The resulting white solid was separated, washed with water and crystallised from methanol-water to give 1.5 parts by weight of product melting at 70-89" (hydrate).

Analysis-Calculated for C I-I NO.H O (percent): C, g4dll8; H, 10.03; N, 4.81. Found: C, 74.42; H, 10.21; N,

EXAMPLE 14 3,4-Dehydro-4- (4-hydroxyphenyl) -1,2,2,6,6-penta methylpiperidine 3.0 Parts by weight of 3,4-dehydro-4- (4'-hydroxyphenyl)-2,2,6,6-tetramethylpiperidine was dissolved in 4 parts by weight of formic acid by warming. After cooling, the solution was treated with 1.1 parts by weight of 37% formaldehyde solution, and this solution heated on a steam bath under a reflux condenser for seven hours. After cooling, the solution was poured into water and basified with sodium carbonate. The white solid was separated, washed with Water and crystallised from methanol-water to give 2.0 parts by weight of product melting at 60100 (hydrate).

Analysis-Calculated for C H NO.H O (percent): C,

16 72.97; H, 9.57; N, 5.32. Found: C, 72.77; H, 9.36; N, 5.10.

EXAMPLE 15 3,4Dehydro-4-(3,5-dimethyl-4'-hydroxyphenyl) 2,2,6,G-tetramethylpiperidine-l-oxyl 10.0 Parts by weight of 3,4-dehydro-4-(3',5'-dimethyl- 4'-hydroxyphenyl) 2,2,6,6 tetramethylpiperidine and 0.8 parts by weight of benzyl trimethylammonium chloride were dissolved in parts by weight of sodium tungstate in a little water. Approximately 10 parts by weight of water was added, care being taken to maintain solution. 13 Parts by weight of 30% hydrogen peroxide was dis solved in 16 parts by weight of methanol and this solution added dropwise with stirring to the amine solution. When the addition was complete the solution was stirred at room temperature for two hours, and then allowed to stand in the absence of light for five days. The solution was then evaporated to dryness under reduced pressure. The residue was dissolved in 40 parts by weight of methanot and treated with 100 parts by weight of water. This solution was extracted into ether and the aqueous phase discarded. The organic phase was washed with water, 2% sulphuric acid and water. After drying (MgSO the ethereal layer was evaporated to dryness to yield 3.4 parts by weight of product. A sample crystallised by slow, partial evaporation of an acetone solution melted at 154-5 C.

Analysis.--Calculated for C H NO (percent): C, 74.42; H, 8.82; N, 5.10. Found: C, 74.66; H, 8.87; N, 4.81.

EXAMPLE 16 3,4-Dehydro-4-(4'-hydroxyphenyl)-2,2,6,6-tetramethylpiperidine-l-oxyl 6.5 Parts by weight of 3,4-dehydro-4- (4-hydroxyphenyl)-2,2,'6,6 tetramethylpiperidine was oxidised, isolated and purified by a method similar to that used in Example 15. The crude residue obtained after the extraction procedure was crystallized from chloroform-petroleum (b.p. 60-80 C.) to give 2.5 parts by weight of product melting at 133-4 C.

Analysis.Calculated for C H NO (percent): C, 73.15; H, 8.18; N, 5.68. Found: C, 73.19; H, 8.13; N, 5.39.

EXAMPLE 17 4(4'-Acetyloxyphenyl)-3,4-dehydro-2,2,6,6-tetramethylpiperidine 5.2 Parts of 4-(4-hydroxyphenyl)-3,4-dehydro-2,2,6,6- tetramethylpiperidine were dissolved in methanol and treated with excess methanolic hydrogen chloride. The solution was evaporated to dryness under reduced pressure and the residue suspended in parts of refluxing acetic anhydride. Concentrated sulphuric acid was added dropwise to the refluxing suspension until complete solution occurred. The solution was heated at reflux for 15 minutes and then evaporated under reduced pressure. The residue was poured into an ice-water mixture which was basified with excess sodium carbonate solution. The mixture obtained was extracted with ether and the aqueous phase discarded. The organic phase was dried over anhydrous magnesium sulphate and evaporated under reduced pressure.

The residue was distilled under reduced pressure to yield 3 parts of the desired product having boiling point C./0.9 mm. and the following elemental analysis C H N0 requires: C, 74.69%; H, 8.48%; N, 5.12%. Found: C, 75.27%; H, 8.58%; N, 5.44%.

EXAMPLE 18 4-(4-Acetyloxy-3',5'-dimethylphenyl)-3,4-dehydro- 2,2,6,6-tetramethylpiperidine 20 Parts of 4-(3',5'-dimethyl-4-hydroxyphenyl)-3,4-dehydro-2,2,6,6-tetramethy1piperidine were converted to the 17 hydrochloride salt and treated with acetic anhydride as in Example 17.

The residue obtained after basification and extraction was distilled under reduced pressure to yield 18.3 parts of the desired product having boiling point 154-6 C./ 0.5 mm. and the following elemental analysis C H NO requires: C, 75.71%; H, 9.03%; N, 4.65%. Found: C, 76.04%; H, 9.15%; N, 4.60%.

EXAMPLE 19 4- (4'-Acetyloxy-3'-cyclohexylphenyl)-3,4-dehydro- 2,2,6,6-tetramethylpiperidine 21 Parts of 4-(3'-cyc1ohexyl-4'-hydroxyphenyl)-3,4-dehydro-2,2,6,6-tetramethylpiperidine were converted to the hydrochloride and treated with acetic anhydride as in Example 17.

The residue obtained after basification and extraction was distilled under reduced pressure to yield 15.4 parts of the desired product having boiling point 176-180 C./0.1 mm. and the following elemental analysis C H NO requires: C, 77.70%; H, 9.36%; N, 3.94%. Found: C, 77.69%; H, 9.37; N, 3.77%.

EXAMPLE 20 4-(3',5'-Dimethy1-4'-octanoyloxyphenyl)-3,4dehydro- 2,2,6,6-tetramethylpiperidine 5 Parts of 4-(3,5'-dimethyl-4-hydroxyphenyl)-3,4-dehydro-2,2,6,6-tetramethylpiperidine were dissolved in 250 parts of xylene and heated to reflux whilst stirred. 1.6 parts of octanoyl chloride dissolved in a small amount of xylene were added to the refluxing solution dropwise. The solution was heated at reflux overnight, allowed to cool and filtered. The filtrate was evaporated to low bulk, dissolved in ether and washed with 2% aqueous sodium hydroxide and water. The organic phase was dried over magnesium sulphate and evaporated under reduced pressure. The residue was distilled under reduced pressure to yield 2.4 parts of the desired product having boiling point 165 C./0.1 mm. and the following elemental analysis.

C H NO requires: C, 77.87%; H, 10.19%; N, 3.63%. Found: C, 77.92%; H, 10.23%; N, 3.39%.

EXAMPLE 21 4- (4'-Benzoyloxyphenyl) -3,4-dehydro-2,2,6,6- tetramethylpiperidine 5 Parts of 4(4'-hydroxyphenyl)-3,4-dehydro-2,2,6,6- tetramethylpiperidine were dissolved in 70 parts of aqueous sodium hydroxide and shaken vigorously with 10 parts of benzoyl chloride. The alkalinity of the solution was maintained by further additions of sodium hydroxide solution. The precipitate was separated and dissolved in hot water. This solution was basified by the addition of aqueous sodium carbonate solution. The precipitate was separated, dissolved in ether and the ethereal solution washed with 10% sodium hydroxide solution and water. The organic phase was dried over magnesium sulphate and evaporated under reduced pressure. The residue was crystallised from a methanol-water mixture to yield 1.1 parts of the desired product melting at 9193 C. and having the following elemental analysis.

C H NO requires: C, 78.77%; H, 7.51%; N, 4.18%; Found: C, 78.52%; H, 7.26%; N, 4.35%.

EXAMPLE 22 4[4(3,5"-di-t-butyl-4"-hydroxybenzoyloxy)phenyl]- 3,4-dehydro-2,2,6,6-tetramethylpiperidine 3.4 Parts of 4-(4'-hydroxyphenyl)3,4-dehydro-2,2,6,6- tetramethylpiperidine were intimately mixed with 8 parts of 3,5-di-t-butyl-4-hydroxybenzoyl chloride. The mixture was heated to 150 and stirred vigorously. Heating was then continued at 120 for 30 minutes. The mixture was cooled, treated with ether and separated. The solid filter was dissolved in a methanol-water mixture and treated with an aqueous sodium carbonate solution. This was extracted with ether and the ethereal layer washed with dilute sodium hydroxide solution and water. The organic phase was dried over magnesium sulphate and evaporated under reduced pressure. The residue was crystallised from petroleum (b.p. -100 C.) to yield 1.5 parts of the desired product melting at 21l-2l3 C. and having the following elemental analysis.

C H 'NO requires: C, 77.71%; H, 8.91%; N, 3.02%. Found: C, 77.50%; H, 8.98%; N, 2.99%.

EXAMPLE 23 4-(4-Methylcarbamoyloxyphenyl)-3,4-dehydro-2,2,6,6- tetramethylpiperidine 15 Parts of 4-(4'-hydroxyphenyl)-3,4-dehydro-2,2,6,6- tetramethylpiperidine were heated at reflux in 1300 parts of dry benzene whilst 3.8 parts of methyl isocyanate were added dropwise. A crystal of 1,4-diazabicyclo[2,2,2] octane was added and the solution heated at reflux for 18 hours. The solution was evaporated to dryness under reduced pressure, the residue dissolved in ether and the ethereal solution washed with dilute aqueous sodium hy droxide solution and water. The organic phase was dried over magnesium sulphate and evaporated under reduced pressure. The residue was crystallised from petroleum (b.p. 80-100 C.) to yield 9.0 parts of the desired product melting at 112-114 C. and having the following elemental analysis.

C17H24N2O2 requires: C, 70.80%; H, 8.39%; N, 9.71%. Found: C, 71.08%; H, 8.55%; N, 9.44%.

EXAMPLES 24 TO 26 38 Parts of polypropylene were homogenised with 0.76 part of n-octadecyl-fi-(4'-hydroxy-3', '-t-butylphenyl)pripionate in a kneading machine over a period of 3 minutes at 200 C. 0.19 parts of the product of one of Examples 4, 6 and 12 was then added and homogenisation continued for another 7 minutes.

This composition was compression moulded with films of 0.1 mm. thickness at 260 C. for 6 minutes, and the films so obtained were then quenched in cold water.

A section measuring 44 mm. by mm. was separated from the 0.1 mm. annealed foil and exposed to light irridation in a fademeter device consisting of a circu lar bank of 28 alternate sunlight and blacklight lamps. The sunlight lamps were 2 feet long, 20 watt fluorescent lamps characterised by a peak emission of 3000 Angstrom units; the blacklight lamps were 2 feet long, 40 watt ultraviolet lamps characterised by a peak emission of 3,500 Angstrom units. The sample was rotated concentrically about the bank of lamps so that the radiation therefrom was uniformly distributed over the section under test.

The exposed sample was examined periodically and the time at which the sample reached 50% of the initial elongation was noted.

The results obtained are summarised in the following table:

Time to 50% initial elongation at;

These results demonstrate the elfectiveness of compounds of the invention as light stabilisers for polypropylene.

1 9 What is claimed is: 1. A compound having the formula H2C/ CH H3C-JJ CHa Ha 1Y1 CH: Y

wherein 4 R and R are selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, sec-butyl, t-butyl, 1,1-dimethylpropyl, 1,1-dimethy1butyl, 2-octyl, cyclohexyl,

l-methylcyclohexyl, benzyl, a,u-dimethylbenyl and phenyl, R and R are hydrogen, methyl or ethyl groups and Y is hydrogen, 0 or methyl. 2. A compound according to Claim 1 which is 3,4- dehydro 4 (4 hydroxy phenyl)-2,2,6,6-tetramethylpiperidine.

3. A compound according to Claim 1 which is 3,4- dehydro 4 (4' hydroxy 3' methylphenyl) 2,2,6,6- tetramethylpiperidine.

4. A compound according to Claim 1 which is 3,4- dehydro 4 (3'5 dimethyl-4'-hydroxyphenyl)-2,2,6,6- tetramethylpiperidine.

5. A compound according to Claim 1 which is 3,4- dehydro 4 (3 t butyl 4' hydroxyphenyl) 2,2,6,6- tetramethylpiperidine.

6. A compound according to Claim 1 which is 3,4- dehydro 4 (3'5' di isdpropyl 4' hydroxyphenyl)- 2,2,6,6-tetramethylpiperidine.

OTHER REFERENCES Roberts et 211., Basic Principles of Organic Chemistry, Benjamin Publishers, p. 806, QD 251 -R 58 C6 1965.

ALAN L. ROTMAN, Primary Examiner US. Cl. X.R.

260-45.8 N, 295 R, 295 CA, 297 B 

1. A COMPOUND HAVING THE FORMULA 